The sneakers are Adidas ultra boosts, a line of running shoes that retails for $US180.00. West was first seen wearing them last May when he headlined Power 106’s PowerHouse 2015 concert at the Honda Center in Anaheim, California, according to the shoe blog. They were available on pre-order, but sold out right away after making their debut on West’s feet.

Another white-on-white pair of ultra boosts was released in June, but they too are apparently sold out.

An Adidas representative didn’t immediately respond to Business Insider’s request for comment.